1. Field of the Invention
The present invention relates to an image processing method at the time of character display in an image apparatus. The image apparatus has a display unit such as a cathode-ray tube (CRT), a liquid crystal display (LCD) or a plasma display, on which RGB signals, a video signal or a composite signal thereof can be displayed. The image apparatus constitutes the whole or part of a television receiver set, a video recording/reproducing apparatus, a computer terminal or a communication terminal equipment.
2. Discussion of the Related Art
Heretofore, for character display, there is a method in which character display is superimposed on a screen the whole of which is painted with a single solid color (a screen painted with a single color is displayed). Further, there is another method in which an earlier signal and a later signal than a character pattern signal are generated to thereby perform edging on the periphery of a character pattern (see Japanese Patent Examined Publication No. Sho. 56-51676, Title of the Invention: CONTOUR ERASING DEVICE OF A CHARACTER SIGNAL).
In the method in which the whole of a screen is painted with a single solid color, however, there arises a disadvantage that a dynamic picture image cannot be seen at all.
On the other hand, in the method in which edging is performed on the periphery of a character pattern, there arises a disadvantage that the circuit configuration becomes complicated to thereby increase the cost.
An object of the present invention is to provide an image processing method in which character display very easy to see is superimposed on a dynamic picture image or a still picture image by a relatively simple circuit configuration at the time of character display.
To achieve the foregoing object, the invention provides an image processing method at the time of character display in an image apparatus having means for superimposing character display on a picture image, wherein a level of xe2x80x9ccolor depthxe2x80x9d of the picture image is automatically controlled when character display is effected.